Masutatsu Oyama (大山 倍達 Ōyama Masutatsu, born Choi Yeong-eui, July 27th, 1923 – April 26, 1994), more commonly known as Mas Oyama, was a karate master who founded Kyokushin Karate, considered the first and most influential style of full contact karate. A Zainichi Korean, he spent most of his life living in Japan